Electrical transformer



Oct. 20, 1925. 1,558,090 I A. A. HOWARD EIJECTRI CAL TRANSFORMER FiledJan 23 -l924 if U @210 7"? I flz/ZZi J J54 n 4 Patented Oct. 20, 1925.

AUSTIN A. HOWARD, OF CHICAGt), ILLINOIS.

ELECTRICAL TRANSFORMER.

Application filed January 28, 1924. Serial No. 687,968.

To all whom it may concern:

Be it known that I, AUs'rIN A. Howam), a citizen of the United States,residing at Chicago, in the county of Cook: and State of Illinois, haveinvented new and useful Improvements in Electrical Transformers,

of which the following is a specification.

This invention relates to improvements in electrical transformers. Oneof the objects of the invention is to provide a transformer which can beeasily and cheaply made and which will be strong and durable. I havehere shown the invention as embodied in a transformer such as is used inconnection with radio apparatus for the amplification of waves at radiofrequency.

In making such transformers, two coils are employed, aprimary coil and asecondary 0011. These coils are arranged in mductive relation to eachother and must be supported properly in this position. By the use of myinvention I am able to do this in a very simple manner.

Other features and advantages of my invention will appear more fully asI proceed with my specification.

In that form of device embodying the features of m invention shown inthe accompanying rawings, Figure 1 is a top plan view of a completetransformer, Fig. 2 is a similar view showing the outer or secondarycoil removed, Fig. 3 is a vertical, sectional view taken through themember which su ports the wires forming the transformer, 1g. 4 is a viewon an enlarged scale taken as indicated by the line 4 of Fig. 1 and Fig5 is a view similar to Fig. 4 showing'a modified form.

As shown in the drawings, 10 indicates a cylindrical sup rting memberhere shown as'inade of insu ating material such as fiber,

bakelite, hard rubber or the like. This cylindrical member is virtuallya section of tubing with a relatively thick wall.

In the'outer surface of the member 10 is cut a. spiral groove 11. Theturns of this groove 11 are spaced apart the distance at which it isdesired to space the turns of the primar coil. The groove 11 is madewith a dept equal to the distance which it is desired to space theprimary or inner coil from the secondary or outer coil. Obviously, thewall of the memberlO must be of suflicient thickness to permit the reuisite depth of the cove 11 and still furnis sufficlent strengt tosupport the wires.

12 indicates the wire forming the inner or primary coil. This wire iswound in the bottom of the groove 11.

The wire 12 may be insulated as shown or it may be bare wire. Preferablthe supporting member 10 is made out of lnsulating material, as statedabove, so that the wire 12 may be bare wire; and when such wire is used"the turns are properly spaced and insulated from each other by thegroove 11.

13 indicates the wire forming the outer or secondary coil and 14 theinsulation thereon. In coils of this kind, the secondary coil isordinarily made of thicker wire as shown. As here shown, the secondarycoil is wound on the outside of the cylindrical support 10, the wirebeing so large that the turns will not enter the grooves 11. As hereshown, there are more turns of the secondary coil than the primary coil.It is obvious, however, that, if desired, smaller wire could be used forthe secondary coil and the turns Wound so that they would not lieparallel with the grooves 11. If so wound, they would not enter thegrooves.

If desired, after the primary coil is wound in the grooves 11, thesegrooves can be filled with some insulating material 15 as shown in themodified form in Fig. 5; and

the secondary wire indicated by l3 -could then be as small as desiredand wound on the outer surface of the support 10 as desired. It' wouldbe prevented from entering the grooves llby the filling substance 15.This substance could be any suitable material and preferably should beinsulating material such as fiber, cement, shellac, or any suitablesubstance.

In either of the forms,'any of the coils could be made either with barewire or insulated wire as desired. If bare wire is used the turns wouldhave to be separated from each other sufficiently to insulate them fromeach other, and obviouslythe support 10 would have to be made ofinsulating material.

The transformer may be mounted in any suitable manner such as by meansof vthe bolts 18 fastening it to any suitable .supports 19. V

While I have shown and described certain embodiments of my invention, itis to be understood that it is capable of many modifications. Changes,therefore, in the construction and arrangement may be made withoutdeparting from the spirit and scope of the invention 88 disclosed in the'in said appended claims, in which it is my intention to claim'allnovelty inherent lngny invention as broadly as possible in view of theprior art.- v o What I claim as new, and desire to. secure by LettersPatent, 1s: p "1. A. device of he character described comprising acylindrical support having a spiral groove in its outer surface, a laidin the bottom of said groove, the depth of said groove being greaterthan the diamstar of the wire laid therein, and another wire wound onthe outer surface of said support and not 1 ing in said groove.

2. A device 0 the character described comprising a cylindrical supportofinsulatingmaterlal having a spira Y ve in its outer surface, a wirelaidin t e bottom of said groove, the depth of said groove being greaterthan the diameter of the wire lai therein, and another wire wound on theouter surface of said support and not lying groove.

. 3. A' device of the character described comprising a-cylindricalsupport havinga 4. A device of the character described i comprising acylindrical support having a spiral groove in its outer surface. aninner spiral coil of wire wound on said support and laid in the bottomofsaid groove, the

ve being greater than the diameter of t e wire laid therein, and anouter spiral coil of wire wound on the outer depth of said surface ofsaid support and not lying in said groove; whereby said inner and outerspiral coils of wire are spaced apart.

In witness whereof, I have hereunto setmy hand and seal this. 19 day ofJanuary,

AUSTIN snowman. q

